98 V70 Alternator -- is there usually a warning light if there is aproblem?

Need some advice -- got road service to jump start my car after they
had run down the battery by setting off the alarm on a prior visit,
and they told me that I needed to replace my battery. I should point
out that the "check engine" light had been on for a while prior to the
battery change and that after the new one was installed, the light
went OUT. I could not swap the battery at the place where I bought it
so I had to go to a nearby place and went to Pep Boys. They told me
they would have to check to make sure the alternator was not also
involved after they installed the battery. After a long time the guy
came out and said that I needed to change my alternator, said that was
what was draining the battery. He gave me a high price and I left. I
then stopped for gas at a place I have gone many times and mentioned
the alternator. The proprietor then came out and I talked with him.
He said he'd take a look under the hood and he put a meter of some
kind on I guess the battery. He then told me that he didn't know
whether the people who had told me I needed a new alternator were just
trying to take advantage (of a female in distress) or whether they
didn't know about European cars. He said that the reading recommended
for American cars is higher and that European cars don't have to
register that high and he thought I may not need an alternator at
all. I am planning a long trip next week. I called the Volvo dealer
even though I don't like this one much (boston) and the person there
told me that there is not usually a warning for an alternator going
bad. But the manual indicates that the warning light that looks like
a battery is indicative of a problem with the charging system which
would included the alternator. What should I do and who should I
believe? I have been driving with the new battery, not a lot, but
driving, for 5 days.

 

I should also include that the proprietor of the gas station/garage
gave me his card which identified him as an "electrical specialist"

 

After 5 days if the alternator was bad you would probably know it by
now as it wouldnt start if it wasnt charging. Most places check
batteries for free because they sell batteries. I would just check the
battery out, if its charged the alternator is fine, you could get a
10$ voltmeter and do it yourself, Motor Running it should be about
13.25-13.4v. With engine off at first it might read near 13.25v and
after sitting maybe overnight about 12.75-12.8v. European cars dont do
it any differently , Lead acid batteries take what they are designed
for and thats it. A 12v battery is about dead or at 25% charge at 12v.
The guy that said you need an alternator was probably lying, but get
it checked or check it yourself with a meter. www.batteryuniversity.com
will teach you more about battery charging and voltages than I know.
If it wasnt charging im sure the light would be on, and its not, you
are starting fine so I wouldnt worry , but I would check the batterys
voltage. When a warning light comes on, dont ignore it next time.

 

to start w/ you have good instincts. i don't like the boston Volvo
dealer & i live thousands of miles away. next consider taking a boy w/
you next time. i know it's sexist but the automotive industry is
sexist. my lady friend is a better driver than i, but the only reason
she gets respect @ the track is that everyone knows if they screw w/
her they will have to deal w/ me. it's a bit pathetic.

if you have a glt then Ransley was fairly right about the #'s. Yank
cars have bigger alternators than rice burners but they are comparable
to Euros of the same size. i would report everyone you talked to to
the BBB. they were all just spinning tales, though the gas station guy
was really just trying not to say anything bad about fellow local
businesses.

the check engine light should never be ignored!!! it resets when you
change the battery because you have just done a cold boot of the ECU.
you should get an alt (battery icon) light if the alternator is not
producing power or the voltage regulator (inside the alt. nowadays)
isn't providing charging voltage. but a bad ballast (battery) will
show up as a check engine error code. i don't know if Volvo was doing
error logs by 1998, but if you are really ar read the log & use the
internet to translate.

btw 12yrs is good for a lead/acid battery. it was time to replace it.
if you spent more than$45 & don't mind a little dirt (wear glove
gloves, dirt & electrical insulators) you were robbed. please study
correct procedure before you attempt any electrical repair. i don't
think it's difficult but i don't think it's difficult to work on high
tension lines & they are 10,000,000,000,000 volts.

electricity is magic to most people -- car owners, home owners,
whomever. it's always a good basis for a scam. strangely enough some
of the best electrical subcontractors, that i know, are women.

 

The warning light will come on if the output from the alternator is very
low or completely absent, but you can have a weak charging system that
is still not bad enough to trigger the light. A better test is to
measure the voltage at the battery with a multimeter with the engine
off, then start the car and measure it again. It should raise to above
13V within a few minutes of starting the car.

 

That doesn't necessarily mean anything. Even someone with experience may
not be familiar with the nuances of any particular car. Most of the
alternator failures I've seen in Volvos are actually the regulator which
is part of the brush pack. The brushes wear out and at first you get
intermittent low output from the alternator and eventually it conks out
completely. In the case of the older Bosch alternators, the regulator is
about 50 bucks and can be replaced separately, I'm not sure what the
newer models use.

 

raise the tach above 2000 for a few seconds that should be enough to
exite the diodes. true there are borderline problems. they have gotten
better. i still think Ransley had the right #'s.

 

for your vehicle the brushes & regulator should come together. never a
bad renewal on a vehicle of your age. it should be alot less than $50.
i would say it's easy, but people tell that it requires finicky hand
skills. it's something i would pay my 14 y/o niece to do. (small, deft
hands) an electrical test is the right first step. i would probably
pull the brushes & have a look anyway, but i'm crazy. the new Bosches
are made in china & best used as small boat anchors.